The invention is based on a coil former with injection-molded encapsulation. In a known coil former of this kind, serving as a component of a speed-of-revolution sensor, a coil wire is guided in curved grooves formed on the surface of the foil former. The coil wire is wound around busbars arranged in the region of the ends of the grooves, and soldered thereto. The coil former and, in particular, the region of the grooves and of the busbars are encapsulated by injection molding with silicone in order to protect the coil wire and damp its vibrations. The coil former, with injection-molded encapsulation, manufactured in this way is enclosed by a pot-shaped metal housing which is connected to the coil former at its circumference, and sealed, by crimping.
It is disadvantageous here that when in particular the grooves are encapsulated by injection molding with a less elastic material than silicone, for example thermoplastic melt, the coil wire in the curved grooves is deflected and stressed transversely with respect to its longitudinal direction. This deflection leads to a shearing and bending stressing which is critical for the coil wire and can lead to a break or prestressing or preliminary damage of the coil wire. Furthermore, by directly winding around the relatively sharply edged busbars, it is possible for the coil wire to suffer preliminary damage even when only one tensile stress occurs.